Aside from the support items and weapons, there's still plenty of stuff to unlock by completing battle objectives and progressing through the story! Like any other .hack game there are wallpapers, music, and more to view at your leisure!
VS The World
Select Versus Rankers and you can see not only where you rank, but a bunch of CPU battle videos. Press the square button and you'll be able to see replays of every non-boss fight you've done for each character! Yup, replays of your best battles are automatically saved for your re-viewing pleasure. And since you can replay all of these battles, you can keep aiming for better and better videos to showoff with... or something!
01.) Model Viewer
From Haseo to Hermit, zoom in out out, rotate, an get nice good view of the character models!
02.) Ultimate Skill Viewer
This allows you to view the eight main chartacters Ultimate Skills at your leisure! Not only that, you can choose to see who they use it against, and choose the stage to view it in! You'll need to progress through the story mode to unlock characters in order to use this to its fullest extent.
03.) Sound Test
Lets you listen to any unlocked background music, of which there are 18, and a large number of voice clips from 11 characters.
04.) Movie Player
Replay any of the games cutscenes, credits roll, and the unlockable OVA Thanatos Report.
05.) Custom BGM
This is useable right after your very first battle in story mode! It allows you to replace the battle theme of any character with music on your PS3's hdd. However you must first unlock a character (by progressing through the story) in order to edit their bgm.
There are 12 of these to be unlocked while playing through the game. You can set them as your background in the game and also view them fullscreen.
These are basically avatars for you to use. There's 50 in total to open up, most of which are also used by people who post in the Yomoyama Records message board.
There are 210 of these thing to obtain! Want to identify yourself as a member of Icolo, the .hackers, or even "mama"? Then set the appropriate one to your VS Pass!
Unlock and choose 1 of 138 short messages to display to other players!
If you choose to start a new playthrough of story mode you'll retain pretty much everything you'd unlocked in previous ones. All Model Viewer, Sound Test, Movie Player, Wallpaper, and VS Pass items will remain unlocked, and in addition to these each of the Support Items and Weapons you earned as well. Ultimate Skill Viewer and Custom BGM re-unlock as you open up characters for use through the Story Mode. The one downside however is that your fight replays are wiped and overwritten with new ones. So if you have some really good replays ya want saved from a previous playthrough it'd be best to back up your save file before starting a new game.